Evaluation the Effect of Chemical and Irradiation Disinfectants on Some Physical and Mechanical Properties of Flexible Denture Base Material

Aims: To evaluate the effect of two methods of disinfections (chemical and irradiation) on (indentation hardness, tensile strength, torsional strength and water sorption) of flexible denture base material by using artificial saliva cycle. Also, to evaluate the effect of immersion cycle (one week, one month and two months) . Materials and methods: Total specimens of this research was 318 specimens, it was divided into 5 groups according to type of disinfectants, they were prepared from flexible resin. They were incubated in a distilled water at 371C for two days for conditioning ,6 specimens for each properties were evaluated as a control. The immersion cycle used was as follows, the specimens were immersed in artificial saliva at 37 1C for 15,5 hr. Then, they were immersed in disinfections solutions for 30 minutes at 451C, for microwave cycle about 6 minutes daily, then they were immersed in distilled water at 212C for 8 hr at night. This cycle was repeated every day for two months. At the end of each period time, the specimens were tested to evaluate the indentation hardness, tensile strength, torsional strength and water sorption properties. The results of the present study were analyzed statistically by (Mean standard deviation, ANOVA and Duncans multiple range test).Results: They showed that, In comparison among disinfectants there was no statistically significant difference at p 0.05 in tensile strength, torsional strength and water sorption properties while there was a significant in the indentation hardness properties. Also, there were no significant difference at p 0.05 in the indentation hardness properties among different times of immersion cycle, while there was a significant difference in tensile strength, torsional strength and water sorption properties after one and two months of immersion cycle. Conclusions: Among disinfectants, microwave irradiation had lowest effect on the indentation hardness, while different immersion cycles in disinfectants had a significant effect on the tensile strength, torsional strength and water sorption properties after one and two months of immersion cycle.